grive: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/grive - from package: grive

You may install the required package with command apt-get install {package}
Error in other languages:
grive: bevel nie gevind nie
grive: comandă negăsită
grive: comando não encontrado
grive: commande introuvable
grive: command not found
grive: käsku ei ole
grive: không tìm thấy lệnh
grive: komanda nerasta
grive: Kommando nicht gefunden.
grive: kommandot finns inte
grive: komut yok
grive: nie znaleziono polecenia
grive: níor aimsíodh an t-ordú
grive: no se encontró la orden
grive: no s'ha trobat l'ordre
grive: opdracht niet gevonden
grive: parancs nem található
grive: perintah tidak ditemukan
grive: príkaz nenájdený
grive: příkaz nenalezen
grive: команда не найдена
grive: командата не е открита
grive: 命令找不到
grive: コマンドが見つかりません